摘要
为了提高再生骨料、粉煤灰的利用率,提高再生混凝土在硫酸盐-干湿循环耦合环境下的耐久性,试验设计了不同取代率下的粉煤灰再生混凝土,采用5%的硫酸钠溶液,在干湿循环机里进行硫酸盐干湿循环试验。试验过程中分别检测混凝土质量损失率、相对动弹模量以及抗压强度损失率,通过3个衡量指标评判出最优配合比。采用MATLAB分别建立最优配合比抗压强度损失率与相对动弹性模量与质量损失率的对数函数平面拟合模型。利用两参数Weibull函数建立寿命预测模型,以此来反映最优配合比试件的剩余寿命。结果表明:在硫酸盐-干湿循环试验中,各组试件的动弹性模量,质量和抗压强度均呈现先上升后下降的趋势。当粉煤灰的替代率为15%时,试件在耦合环境下的耐久性最强,通过预测试件最多经受98次硫酸盐-干湿循环后才会失效。
In order to improve the utilization rate of recycled aggregate and fly ash,and improve the durability of recycled concrete in the environment of sulfate dry wet cycle coupling,the experiment designed the recycled fly ash concrete with different replacement rate,using 5%sodium sulfate solution,and carried out the sulfate dry wet cycle test in the dry wet cycle machine.During the test,the concrete quality loss rate,relative dynamic modulus and compressive strength loss rate are detected respectively,and the optimal ratio is determined by three indicators.MATLAB was used to establish the logarithmic function plane fitting models of the loss rate of compressive strength,relative dynamic modulus of elasticity and loss rate of mass.Using the two parameter Weibull function,a life prediction model is established to reflect the remaining life of the optimal ratio specimen.The results show that the dynamic modulus of elasticity,mass and compressive strength of each group of specimens increase first and then decrease.When the replacement rate of fly ash is 15%,the durability of the specimen is the strongest under the coupling environment.It is predicted that the specimen will not fail until it undergoes 98 times of sulfate wet and dry cycles at most.
作者
冯琦
王宇斌
FENG Qi;WANG Yubin(Department of Architectural Engineering,Xi′an Institute of Foreign Affairs,Xi′an 710077,China;School of Resource Engineering,Xi′an University of Architecture and Technology,Xi′an 710055,China)
出处
《混凝土》
CAS
北大核心
2021年第5期42-45,50,共5页
Concrete
基金
国家自然科学基金项目(51974218)。
